William c



W. C. BANKS.

FUSE.

-APPLICATION FILED OCT- 26. 1918.

1 ,3 1 5, 590 Patented Sept. 9, 1919.

IlIIIIIIIIIIIIIIIIIIIIII!IIIIIII/I'IIIIIIIIIIIIIIIIIIII 4' 3 Suva-W01 UNITED STATES PATENT OFFIC.

WILLIAM; C. BANKS, OF JERSEY CITY, NEW JERSEY, ASSIGNOR T0 AJAX ELECTRIC COMPANY, OF JERSEY CITY, NEW JERSEY, A. CORPORATION OF NEW J ERSEY.

FUSE.

Specification of Letters Patent. Patented Sept, 9, 1919,

Application filed ember as, 1918. Serial No. 259,799.

To all whom it'mag concern:

Be it known that 1, WILLIAM G. BANKS, a citizen of the United States, residing at J ersey City,.county of Hudson, and State of New J ersey, have invented 'certain new and useful Improvements in Fuses, of which the following is a specification.

This invention relates to fuses of the type commonly employed in electric circuits for opening such circuits when the current fiowing therein exceeds a predetermined amount. The invention has reference particularly to fuses of this character in, which the fusible strip is suitably inclosed and is so held that a disrupted strip may be readily removed and a new one inserted in its place. The invention is directed particularly to the means whereby the "ends of such a renewable fusible strip are gripped and held, and may be considered an. improvement on the structure described in my Patent No. 1,124,194, improvements in fuses, dated January 5, 1915. 1

In fuses of this character, it is important that the ends of the fusible strip be gripped very tightly so that the strip. will be held in the proper position and good'electrical contact shall made therewith. In my present invention, devices are provided whereby the strip is firmly held in such a manner that there is no danger of the parts working loose under vibration, the parts being simple in character, readily manufactured and assembled and taken apart.

The objects of my invention reside in the improved details of construction and combinations of parts hereinafter more fully described. In the preferred form of my device, the fuse strip is gripped at each end by a pair of members lying on opposite sides of the fuse strip, the exterior surfaces of which members are tapered outwardly from each end toward the central portion. The inner ends of these members are adapted to seat in a correspondingly tapered annular seat formed in a member which is mounted within a metal ferrule which is threaded or :otherwise secured on each end of the tubular casing for the fuse strip. These members having the annular seats are adapted to act as stops against which the ends of the tubular casing abut when the ferrules are screwed into place. Annular end members are provided having tapered seats therein, corresponding to the taper of the outerends of the gripping-members, these end members being screwed into the outer ends of the ferrules into binding contact with the outer ends of the gripping members. With such a construction, a wedging action takes place between the gripping members andboth of the members having tapered seats therein engaging the same. The gripping members, and preferably both of the members engagmg the same at each end, and the ferrules,

' being formed of conducting metal, good electrical contact is established, and the fuse strip is clampedin an exceedingly positive manner. Furthermore, it will be noted that the gripping members are symmetrically formed so that the same may be inserted interchangeably from either end, thus simplifying the assembly of the parts.

In order that my invention may be more clearly understood, attention is hereby directed to the accompanying drawings forma preferred embodiment of my invention. In the drawings, Figure l is a longitudinal section of a fuse constructed in accordance with my invention. Fig. 2 is a view similar to Fig. 1, the plan of the section being at right angles to that of Fig. 1, the fuse strip and gripping members being shown'in side elevation. Fig. 3 is an end view of the fuse. Fig. 4 is a similar view with the locking end member removed. Fig. 5 is a similar view with thegripping members also removed. Fig. 6 is an enlarged section through one end of a modified form of device, and Fig. 7 is a cross section on line 7-7 of Fig. 6.

Referring to the drawings, the fuse strip 1 is formed of a suitable metallic, composition and is shown as contracted at the central portion thereof in the usual manner. The strip 1 is placed within an inclosing tube 2 made of fiber or other suitable insulating and non infiammable composition. Ferrules 3, formed of a suitable conducting metal, are securely mounted on the ends of the tube 2 so as to extend for a distance beyond the tube at each end. Preferably, the tube 2 is provided with screw threads on its exterior adjacent each end, and the ferrules I ing part of this application and illustrating erably, the members 4 take the form of separable rings formed of a suitable conducting metal and screw threaded on their peripheries so that they may be adjusted into position at a desired point in the length of the ferrules 3, and also for the purpose of simplifying the construction of the parts. The members 4 may be readily screwed into position by providing the same with openings 5 which may be engaged by the projections on a suitable instrument. Each member 4 is provided-with an annular tapered seat 6 which tapers outwardly from the inner to the outer surface thereof.

The wedging members comprise a pair of metal blocks 7, 7, each of which has a flat or plane inner surface 8 adapted to engage the sides of the fuse strip 1. Each end of one of 'the gripping members preferably constitutes a half circle as is indicated in Figs. 3 and 4. The exterior surface of a pair of gripping members, taken together, at the portion 9 intermediate the ends is preferably circular in shape, and of a diameter greater than that of the ends of the gripping members and somewhat greater than the largest diameter of the seat 6 of the member 4. The outer surfaces of the Wedge-shaped members incline outwardly 9 so that a pair of gripping members taken together constitute a double wedge.

A pair of gripping members 7 are posit oned at each end of the device on opposite sides of the fuse strip with the outer tapered surfaces of the inner ends of the gripping members seated in the annular seat 6 of the member 4 at each end. The end member 10 is adapted to fit within the ferrule 3 and to be movable axially thereof, one of these end members being provided for each end of the device. Each member 10 is provided with an inwardly extending tapered opening therein which is adapted to engage the outer tapered end portion of the gripping members 7, the result of forcing member 10 into position being to force the gripping members into a tight Wedging engagement with the member 4* at each end and to force the gripping members into a similar tlght wedging engagement with the member 10 at each end, the fuse strip being tightly clamped between each pair of gripping members, the fuse strip being clamped the more 'tlghtly, the farther member 10 is forced into the ferrule 3. Preferably, each member 10 comprises a metal annulus havmg screw threads on its periphery adapted to be screwed into the threaded bore of the ferrule 3, openings 11 being preferably provided 1n each member 10 for engagement with projectio ns of a suitable instrument such as a spanner wrench, so that the member 10 may be readily screwed into place.

It will be noted that in the preferred form of my invention, the gripping members are exactly alike and each of the same has ex-.

actly the same taper at each end of the same.

care in slipping the wedging members into place, since they may be inserted in place,

either end first, and in any position so long as the flat inner surfaces 8 thereof aline with the flat sides of the fuse strip.

In assembling the device, the members 4 being adjusted at suitable points in the lengths of the ferrules 3, the ferrules are screwed into position on the ends of the tube 2 until the ends of the tube abut firmly against the members 4. The gripping members 7 may then be dropped into place at one end with the end portion of the fuse strip extending between the same. It is not necessary to mount the gripping members in place with the fuse strip already inserted between them,.since the fuse strip may readily be pressed down between the gripping members when the latter are mounted on their seat in member 4, the members being Slightly pressed apart by the insertion of the fuse strip. The end member 10 is then screwed into position in the end of the ferrule until the same has been sutliciently tightened about the gripping members 7 which are at the same time moved inwardly lengthwise of the tube sufficiently to wedge the same tightly against their seat in member 4. The gripping members are then mounted in position on opposite sides of the fuse strip at the opposite end, and'the end member 10 screwed into place at this end. The fuse strip may, of course, extend beyond the ends of the gripping members if desired. It will be noted that the openings 5 and 11 through the members 4 and 10 form passageways from the interior of the tube 2 so that any in which-the gripping members 7, 7 are provided with ribs or keys 12, adjacent one end, which are adapted to fit into corresponding recesses the tapered seats in members 4, to prevent possibility of members 7 turning, while members 10 are being screwed into place.

It is obvious that the construction described provides means whereby the parts are all efliciently locked together, the member 4 forming in effect a lock nut for the tube\2 and pressure of the gripping members being resisted by both the members 4 and 1.0 at each end. It also will be noted that when the members 4 are formed of metal, the gripping members will have an entirely metal to metal contact, insuring positive and firm engagement of all the parts. It is to be understood that my invention is not limited strictly to the exact do tails of construction described but is as lac . wardly tapered annular seat, gripping members on opposite sides of the fuse, having their outer surfaces taper outwardly from each end toward the intermediate section, adapted to seat with their inner end portions within said seat, and an end member having an inwardly-tapered opening therein, said member fitting within and be ing adapted to be moved axially into the outer end of said ferrule with its said opening having wedging engagement with the outer portions of said gripping members.

- 2. Tlfe combination of a fuse, a tubular inclosure therefor, having an outwardly-tapered seat therein adjacent an end, gripping members on opposite sides of the fuse, having their outer surfaces taper from each end toward the intermediate section, adapted to seat with their inner end portions within said seat, a ferrule secured on the end of said tube, and an end member having an inwardly-tapered opening therein,said member fitting within and being adapted to be moved axiall into the outer end of said ferrule with its said opening having wedging engagement with the outer portions of said gripping members, to force the inner end portions of said members into wedging engagement with said seat.

3. The combination of a fuse, a tubular inclosure therefor, having anoutwardly-tapered seat therein adj aoent an end, gripping members on opposite sides of the fuse, having their outer surfaces taper from each end toward the intermediate section, said members being reversible, and adapted to seat with either 'end portion within said seat, and means adaptedto exert pressure against the outer tapered end portions of said members to force their inner end portions into wedging engagement with said seat, and to hold said members in such position, said means having a tapered opening' therethrough, through which said gripping members and said fuse extend.

4. The combination of a fuse, a'tube of insulating material inclosing the same, a

metal ferrule adapted to be screwed on the outer end of said tube, and having an inwardly-extending annular stop therein,

internally-threaded metal ferrule adapted to be screwed on the outer end of said tube, a

threaded metal annulus adapted to be screwed into said ferrule to form a stop for the end of said tube, said annulus having a tapered opening therein, wedge blocks adapted to grip said fuse between them and seat within said opening, and a threaded end member adapted to be screwed into the outer end of said ferrule, in engagement with said wedge blocks, to force the latter into, wedging engagement within said tapered opening.

6. The combination of a fuse, a tube of insulating material inclosing the same, having externally-threaded end portions, inte- -of each within one of said seats, and annular end members, exteriorly threaded, and having inwardly-tapered seats formed therein, adapted to be screwed into the ends of=said ferrules and into wedging engagement with the outer portions of said gripping members.

This specification signed and witnessed this 18th day of October, 1918.

WILLIAM G. BANKS.

I Witnesses:

Damn SMITH, I. MoIn'rosn.

'riorlyhreaded ferrules screwed on said end 

